[Beowulf] first cluster

[Glen Beane]

On 7/13/10 12:29 AM, "Rahul Nabar" <rpnabar at gmail.com> wrote:

> On Mon, Jul 12, 2010 at 2:02 PM, Gus Correa <gus at ldeo.columbia.edu> wrote:
>> Consider disk for:
>> 
>> A) swap space (say, if the user programs are large,
>> or you can't buy a lot of RAM, etc);
> 
> Out of curiosity, is there the possibility of running a "swapless"
> compute-node? I mean most HPC nodes already have fairly generous RAM
> and once swapping to disk starts performance is degraded (severely?).

at a previous job (seems like a million years ago) we had a Top-500 cluster
with completely diskless compute nodes - no local disk for swap or /tmp
space. 

My current cluster has a small amount of swap on each node (~1GB) and we
avoid swapping. Our attitude still is swapping is not an option - it is an
indication that we should be decomposing our problem further and
distributing it across more nodes. This cluster happens to have a local OS
install.

We're deploying a new cluster in the next month or so based on the 8-core
magny-cours with 128GB RAM per node. The nodes will network boot but we have
local disks for /tmp and a very small amount of swap.



-- 
Glen L. Beane
Software Engineer
The Jackson Laboratory
Phone (207) 288-6153